Step-by-step-movement controller



J. E. PLEW.

STEP-BY-STEP MOVEMENT CONTROLLER. APPLICATION FVILED DEC 20. 1920.

1,436,821. I Patented Nov. 28, 1922'.

2 SHEETS-SHEEI l.

Z 4 WM J. E. PLEW.

STEP-BY-STEP MOVEMENT CONTROLLER.

APPLICATION FILED DEC 20. I920.

1 ,436,821 Patented Nov. 28, 1922.

2 SHEETSSHEET 2.

Patented Nov. 28, 1922.

PATENT OFFICE.

JAMES E. PLEW, OF CHICAGO, ILLINOIS.

STIEP-BY-STEP-MOVEMENT CONTROLLER.

Application filed December 20, 820.

T 0 all whom it may concern Be it known that L JAMES E. PLEw, a citizenof the United States, residing at (lliiago, county of ook, State oflillinois, have invented a certain new and useful linproven'ient inStep-byhep-lilovenient Coin trolle and declare the following to be afull, clear. and exact description of if e sanie, such as will enableothers skilled in the art to which it pertains to make and use the same,reference being had to ill"..ilCCOlfl panyinpdrawings, which form a partof this specificati' u.

My in vention has for its object, specifically considered, to produce asimple and novel. attaclnnent tor a calculating machine or the likewhich will insure a step by step move nient ot the carriage such toat"the carriage will not accidentally be moved through a greater number oisteps than desired.

lln such devices of this kind with which am familiar the blow or shockof stopping the carriage comes upon the actuating; lever and the toothedrack with which the lever eo-operates to hold the arriagrc in any delltl position. A. further object of the present invention is to produce astep by step mechanism that will relieve the parts which definitely holdor lock the carriage in its various positions from tl e shock ofstopping the carriage and permit them to more relatively to each otherat the instant of stopping. freely and without a wearing; action betweenthem.

in carrying out my invention l find that it may be embodied in a simplemechanism which may be fastened to existing machines and therefore. myinvention, in its broader aspects, may be said to have for its object toproduce a simple and novel mechanism by means oi which the movement of atraveling member may he confined to a step by step inovonient.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claims: but.for a lull understandinpof my invention and of its objects andadvantages, reference may be had to the tollowing detailed descriptiontaken in connection with the acconupanying drawing. wherein:

Figure l is a front elevation oi so much of a calculating machine as isnecessary to illustrate the application of my invention.

Serial No. 431,884.

thereto, the device being shown in a position of rest;

Fig. 2 is a view similar to Fig. 1. showing the relation of the partswhen the can riage has been moved toward the right a distance somewhatless than a full step 3 is a view similar to Figs. 1 and 2, showing therelations of the parts upon the completion of a step, just prior to therelease (it the auxiliary actuating lever used to move the carriagenirough that step;

Fig. l is a section taken approximately on line of 1;

Fig. 5 is section taken approximately on line 5-5 of 2; and

Fl is a top plan view of the supporting asc tor the carriage showing therelation between the usual toothed rack and the toothed member or racl:forming part at the attachment.

Referring to the drawing. 1 represen s the base of a calculatingmachine. on which base is mounted a slidablc carriage. 2. niovable inopposite directions. The base oi the machine rests on a suitable slab orsupport. ii. The carriage has mounted thereon and movable therewith asuitable shitting device which. in the arrangement shown, consists of aspring-pressed locking lever. l,

projectingfrom the front hereof and swinging: in a plane at right anglesto the direction oi moven'ient the carriage together with a rack formedby cutting notches, in the top taco ot' the base in position to beengaged by the inner end of the lever. These parts are old and welllcnown, will appear by reterencc to the patent to .l ahnz, l lo. 9%,367,dated January ll. 1910, tor example, and are used by me only tor thepurposes of illustration.

In lieu of the stationary finger pieces usually fixed to the. carriageon opposite sides oi the controlling lever, employ zurrw able fingerpieces, 6, 3. each carried on one arm of a bell crank lever. T, mountedto oscillate on a supporting pin or stud H. A. spring, 9, between eachof the pins or studs, 8, and the corresponding bell crank lever tendsconstantly to hold the lever in such position that the finger piecethereon will be vertical as shown in Fig. l and, so tar as the righthand finger piece is conceriwd, also in Figs. 2 and 3. There fixed tothe ontrollinglever, 4, a dQPQIltllllg post, 10,

having an enlarged head, 11, producing upwardly-directed shoulders onopposite sides of the post at the lower end. ()ne arm of each of thebell crank levers normally stands approximately horizontal and, on thefree end thereof, is hung a pawl, 12, having a tooth, 13, adapted tointerlock with the adjacent side of the head 11; there being a spring,14, between each pawl and its supporting lever, which spring tendsconstantly to press the free end of the pawl toward the member 10.

On the front of the base of the machine is fixed a bar, 15, havingteeth. 16. (llStl'lblltHl along its upper edge. The spacing between theteeth 16 is equal to the spacing between the notches, 5, with which thecontrolling lever, 4, co-operates. The free end of each of the pawls,13, is in the form of a downwardly-projecting nose, 1?, adapted to enterbetween the teeth on the stationary rack bar, 15, when the correspondingfinger piece is pressed laterally.

The parts are so proportioned that when one of the finger pieces ispressed "laterally, the pawl carried thereby pulls down on the head 11attached to the controlling, lever of the carriage, so as to lift theinner end of the lever out of the particular notch, 5, with which ithappens to be engaged. Thereupo'n, if the lateral thrust on the fingerpiece is great enough, the carriage starts to travel. The nose of thepawl which has been depressed enters between two of the teeth on thebar, 15, before the main controlling lever is entirely free from thenotch out of which it is lifted. Consequently as the carriage travelslaterally, one of the teeth, 16, will engage the nose of the oncomingpawl, bringing the free end of the pawl to rest and permitting thepivoted end to travel ahead. The result is that the pawl which for thetime being happens to be the actuating pawl, is disconnected from thehead on the main controlling lever as illus trated in Fig. 2. There isnow nothing to prevent the controlling lever from assuming a lockingposition whenever the carriage has traveled far enough to bring theinner end of the locking lever into registration with the notch next tothe one out of which .the locking lever has just been lifted. However,in the positions of the parts as shown in Fig. 2, the inner end of thelocking or controlling lever is still resting on a high portion of thebase between two of the notches 5. As the movement of the carriagecontinues, the arm of the bell crank lever which is carrying theactuating pawl engages with a pin or stop 18, on the carriage and thuslimits the swinging movement of the bell crank lever, the shoulder ortooth, 13, on the actuating pawl comes in contact with the upper edge ofone of the teeth 16, and the nose of the actuating pawl engages with theadjacent side of the next tooth, l6, behind it; the final conditionbeing that illustrated in Fig. 3 where the movement of the carriage hasbeen arrested by reason of the fact that the actuating pawl has become alever fulcrumed at its middle upon one of the teeth 16 and engaged atits lower end by one of the other teeth, whereby a continued movement ofthe upper ends of the pawl, in the direction in which it has been going,is impossible. This final condition is reachedjust as the maincontrolling or locking lever registers with the slot into which itsinner end is to drop. Therefore, as the carriage comes to rest, thefront end of the main locking or controlling lever flies up and the rearend seats itself in the proper notch without being pressed againsteither of the side bounding walls of the notch, and therefore withoutbeing forced to slide over either of such walls while in frictionalcontact therewith; the main controlling or locking lever being freelymovable up and down. As soon as the finger piece by means of which thecarriage has been pushed along is released, the parts all assume thepositions illustrated in Fig. 1 except, of course. that the carriage hasmoved ahead one step.

The same cycle of operations is carried out when the carriage is shiftedin one direction as when it is shifted in the other direction. it beingonly a question which of the finger pieces is actuated.

It will thus be seen that I have produced a simple and novel attachmentwhich is all on the exterior of the machine, so that it may be appliedto an existing machine without altering the latter. Furthermore. I amable to obtain the step by step movement with the use of finger piecesplaced in the same positions as heretofore. the only difference beingthat they are movably supported instead of being stationary. It willalso be seen that by placing on the attachment the whole work ofbringing the carriage to rest, wear in the carriage-locking mechanismwill be reduced to a minimum because of the entire freedom of thelocking lever to move up and down without frictionally engaging thestationary part, at the time the carriage is brought to rest afterhaving moved a step in one direction or the other.

lit will further be seen that if it is desired to move the carriage inone direction or the I other without making it go step by step, this canbe accomplished by simply pressing down on the outer end of thecontrolling or locking lever, without taking hold of either. fingerpiece, but using the controlling or locking lever as a finger piece formoving the carriage.

While l have illustrated and described with particularity only a singlepreferred form of my invention, I do not desire to be limited to theexactstructural details thus illustrated and described;but intend tocover all forms and arrangements which come within the terms employed inthe definitions of my invention constituting the appended claims.

I claim:

1. The combination with a movable carriage, of a vertically-swinginglocking lever mounted on said carriage, a horizontal stationary toothedbar arranged below said lever, finger pieces movably supported on thecarriage on opposite sides of said lever, a part depending from saidlever and having at its lower end upwardly directed shoulders onopposite sides thereof, pawls associated with said finger pieces andnormally engaging with said shoulders, each of said pawls having a partadapted to enter between two of the teeth on said bar when thecorresponding finger piece is actuated in a direction to move thecarriage.

2. The combination with a movable carriage, of a. locking or controllinglever mounted on the carriage and movable in a vertical plane, two bellcrank levers mounted on the carriage on opposite sides of the lookinglever and each having an arm extending vertically and another armextending toward the locking lever, a finger piece on the vertical armof each bell crank lever, a pawl hung on the free'end of the horizontalarm of each bell crank lever, a part depending from the locking leverbetween said pawls and having at its lower end upwardly-disrected'shoulders on opposite sides thereof en gaged by the pawls, astationary toothed bar lying below said pawls and in the same verticalplane, said pawls having noses at their lower ends adapted to enterbetween the teeth on the bar when the finger pieces are actuated todepress the pawlsancl draw down the locking lever.

3. The combination with a movable car ria'ge, of a locking andcontrolling lever mounted on the carriage so as to be capable ofswinging in a vertical plane, a stationary rack co-operating with thelever to lock the carriage in any one of a plurality of positions, astationary toothed bar parallel with said rack, and mechanism mounted onthe carriage and co-operating with said toothed bar to depress thelocking lever to release it from the rack, to cause the locking lever tobe released when the carriage. has moved a distance less than thespacing of the teeth in the rack and in the bar, and to form a positivestop for the carriage when the movement of the carriage has continuedfar enough to permit the locking lever to drop freely bet-ween the teethof its co-operating rack.

4. The combination with a movable carriage, of a vertically swinginglockinglever mounted on the carriage, a horizontal stationary toothedbar below said lever, a finger piece movably mounted on the carriagebeside said lever, a stop for limiting the move- .ment of the fingerpiece in one direction,

and a pawl carried by said finger piece and normally engaging with saidlever so as to carrv said lever into a release position when the ting t1piece is actuated, said pawl having a pal adapted to extend between twoof the teeth on said bar before the finger piece'is arrested by said stoIn testimony whereof, I sign this specifi-,

cation.

JAMES E. PLEW;

